Method of receiving a disaster warning message in mobile communication system

ABSTRACT

Disclosed is a method of receiving a warning message in wireless communication system. A terminal (UE) monitors a physical downlink control channel to receive a specific Radio Network Temporary Identifier (RNTI) that indicates an existence of the warning message, and the terminal receives the warning message through a control logical channel that maps with a downlink shared channel if the warning message is existed.

This Nonprovisional application claims priority under 35 U.S.C. 119(e)to U.S. Provisional Application Nos. 61/037,681 filed on Mar. 18, 2008,61/038,035 filed on Mar. 19, 2008, and 61/073,748 filed on Jun. 18,2008. This application also claims priority under 35 U.S.C. §119(a) onPatent Application No. 10-2009-0022685 filed in the Republic of Korea onMar. 17, 2009, the entire contents of all are hereby incorporated byreference into the present application.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of receiving a disasterwarning message (or any warning message) in wireless communicationsystem. More particularly, a terminal (UE) set or establish a controllogical channel broadcasting a warning message, periodically monitors awarning message broadcasting time period, receives a Radio NetworkTemporary Identifier (RNTI) through a Physical Downlink Control Channel(PDCCH) during the warning message broadcasting time period, andreceives the warning message through a control logical channel that mapswith a downlink shared channel.

2. Description of the Related Art

FIG. 1 shows an exemplary network structure of an Evolved UniversalMobile Telecommunications System (E-UMTS) as a mobile communicationsystem to which a related art and the present invention are applied. TheE-UMTS system is a system that has evolved from the UMTS system, and itsstandardization work is currently being performed by the 3GPP standardsorganization. The E-UMTS system can also be referred to as a Long-TermEvolution (LTE) system.

The E-UMTS network can roughly be divided into an Evolved UniversalTerrestrial Radio Access Network (E-UTRAN) and a Core Network (CN). TheE-UTRAN generally comprises a terminal (i.e., User Equipment (UE)), abase station (i.e., eNode B), and an Access Gateway (AG) that is locatedat an end of the E-UMTS network and connects with one or more externalnetworks. The AG may be divided into a part for processing user trafficand a part for handling control traffic. Here, an AG for processing newuser traffic and an AG for processing control traffic can becommunicated with each other by using a new interface. One eNode B mayhave one or more cells. An interface for transmitting the user trafficor the control traffic may be used among the eNode Bs. The CN maycomprise an AG, nodes for user registration of other UEs, and the like.An interface may be used to distinguish the E-UTRAN and the CN from eachother.

Radio interface protocol layers between the terminal and the network canbe divided into a first layer (L1), a second layer (L2) and a thirdlayer (L3) based on three lower layers of an Open System Interconnection(OSI) standard model widely known in communications systems. A physicallayer belonging to the first layer provides an information transferservice using a physical channel. A Radio Resource Control (RRC) layerlocated at the lowest portion of the third layer controls radioresources between the terminal and the network. For this purpose, theRRC layer allows RRC messages to be exchanged between the terminal andthe network.

FIG. 2 shows radio interface protocol architecture between a terminaland E-UTRAN based on 3GPP radio access network standards. The radiointerface protocol in FIG. 2 have horizontal layers comprising aphysical layer, a data link layer and a network layer, and has verticalplanes comprising a user plane for transmitting user traffic and acontrol plane for transmitting control signals. The protocol layers inFIG. 2 can be divided into a first layer (L1), a second layer (L2) and athird layer (L3) based on three lower layers of an Open SystemInterconnection (OSI) standard model widely known in communicationssystems. Hereinafter, each layer in the radio protocol architecture inFIG. 2 will be described.

A first layer, as a physical layer, provides an information transferservice to an upper layer using a physical channel. The physical layeris connected to its upper layer, called a Medium Access Control (MAC)layer, via a transport channel. The MAC layer and the physical layerexchange data via the transport channel. Data is transferred via aphysical channel between different physical layers, namely, between thephysical layer of a transmitting side and the physical layer of areceiving side. The physical channel is modulated based on an OrthogonalFrequency Division Multiplexing (OFDM) technique, and utilizes time andfrequency as radio resources.

The MAC layer located at the second layer provides a service to an upperlayer, called a Radio Link Control (RLC) layer, via a logical channel.The RLC layer of the second layer supports reliable data transmissions.The function of the RLC layer may be implemented as a functional blockin the MAC layer. In this case, the RLC layer may not exist. A PacketData Convergence Protocol (PDCP) layer of the second layer, in the radioprotocol user plane, is used to efficiently transmit IP packets, such asIPv4 or IPv6, on a radio interface with a relatively narrow bandwidth.For this purpose, the PDCP layer reduces the size of an IP packet headerwhich is relatively great in size and includes unnecessary controlinformation, namely, a function called header compression is performed.

A Radio Resource Control (RRC) layer located at the lowest portion ofthe third layer is only defined in the control plane. The RRC layercontrols logical channels, transport channels and physical channels inrelation to establishment, re-configuration and release of Radio Bearers(RBs). Here, the RB signifies a service provided by the second layer fordata transmissions between the terminal and the E-UTRAN. If an RRCconnection is established between the RRC layer of the terminal and theRRC layer of the radio network, the terminal is in the RRC connectedmode. Otherwise, the terminal is in an RRC idle mode.

A Non-Access Stratum (NAS) layer located at an upper portion of the RRClayer performs functions, such as session management, mobilitymanagement and the like.

One cell constructing an eNB is set to one of bandwidths of 1.25 MHz,2.5 MHz, 5 MHz, 10 MHz, 20 MHz and the like, so as to provide downlinkor uplink transmission services to multiple terminals. Here, differentcells may be set to provide different bandwidths.

Downlink transport channels for transmitting data from a network to aterminal may comprise a Broadcast Channel (BCH) for transmitting systeminformation, a Paging Channel (PCH) for transmitting paging messages anda downlink Shared Channel (SCH) for transmitting other user traffic orcontrol messages. Traffic or control messages of a downlinkpoint-to-multipoint service (multicast or broadcast service) may betransmitted either via a downlink SCH, or via a separate downlinkMulticast Channel (MCH). In addition, uplink transport channels fortransmitting data from a terminal to a network may comprise a RandomAccess Channel (RACH) for transmitting an initial control message and anuplink Shared Channel (SCH) for transmitting user traffic or controlmessages.

Logical channels which are located at an upper portion of transportchannels and mapped to the transport channels include a BroadcastControl Channel (BCCH), a Paging Control Channel (PCCH), a CommonControl Channel (CCCH), a MBMS point-to-multipoint ControlChannel/Multicast Control Channel (MCCH), a MBMS point-to-multipointTraffic Channel/Multicast Traffic Channel (MTCH), and the like.

FIG. 3 shows a transmission on a control channel according to therelated art.

A physical channel is composed of multiple sub-frames arranged on a timeaxis and multiple sub-carriers arranged on a frequency axis. Here, asingle sub-frame includes a plurality of symbols on the time axis. Onesub-frame is composed of a plurality of resource blocks, each of whichincludes a plurality of symbols and a plurality of sub-carriers. Also,each sub-frame can use particular sub-carriers of particular symbols(e.g., a first symbol) at the corresponding sub-frame for a PhysicalDownlink Control Channel (PDCCH), namely, a L1/L2 control channel. Onesub-frame is time duration of 0.5 ms. A Transmission Time Interval (TTI)as a unit time for which data is transmitted is 1 ms corresponding totwo sub-frames.

FIG. 4 is a block diagram of a network structure for a cell broadcastservice. As illustrated in FIG. 4, CBS messages originate in a pluralityof cell broadcast entities (hereinafter abbreviated CBEs) connected to acell broadcast center (hereinafter abbreviated CBC). The CBE separatesthe CBS message into a plurality of pages. The CBC is one node of a corenetwork that performs a scheduling function by managing the CBS message.Iu-BC is an interface defined between the CBC and the RNC using aservice area broadcast protocol (hereinafter abbreviated SABP). The CBCcan give the RNC a broadcast order for a new message or enable aprevious broadcast message to be modified or terminated using the SABP.The RNC performs a scheduling function for a CBS message delivered bythe CBC and a broadcasting function to transmit the message to aspecific cell using a BMC protocol. The RNC has a broadcast/multicastinter-working function (hereinafter abbreviated BMC-IWF) above a BMClayer to perform an interpreting function for a message and informationdelivered from the CBC. The UE receives a CBS message broadcast by theUTRAN. Examples of BMC messages used in the BMC protocol are a CBSmessage delivering user information, a schedule message facilitatingreception of a CBS message by a UE and a CBS41 message delivering ashort message delivered from an ANSI41 network. All the messages aretransmitted from the UTRAN to the UE in uni-direction through a logicalchannel such as CTCH (Common Traffic Channel). The UE can reduce itsbattery consumption by performing discontinuous reception (hereinafterabbreviated DRX) using information in the schedule message transmittedby the UTRAN through CTCH (Common Traffic Channel).

In a conventional Cell Broadcast Service (CBS) scheme, schedulinginformation related to a warning message is transmitted through a CommonTraffic Channel (CTCH). Therefore, in a related art, this cause a greatdrawback that a terminal can not promptly or quickly receive schedulinginformation of the warning message since the terminal usually receives atraffic channel after receiving of the control channel first. Further,in general, the CTCH is mapped with a Forward Access Channel (FACH),which is statically or persistently scheduled transport channel.Therefore, using of the CTCH channel to transmit the schedulinginformation of the warning message may cause a great drawback ofinefficient usage of a radio resource(s).

SUMMARY OF THE INVENTION

The present invention is to provide a method for efficiently receiving awarning message, by a terminal, with a minimum delay while efficientusage of radio resource(s) is achieved.

To implement at least the above feature in whole or in parts the presentinvention may provide a method of receiving a warning message in mobilecommunication system, the method comprising: receiving controlinformation related to the warning message through a first downlinkcontrol channel; and receiving the warning message based on the receivedcontrol information through a second downlink control channel.

The present invention may also provide a method of receiving a warningmessage in mobile communication system, the method comprising:monitoring a physical downlink control channel (PDCCH) periodically fora certain time period; receiving a specific Radio Network TemporaryIdentifier (RNTI) related to the warning message through the PDCCH; andreceiving the warning message based on the specific RNTI through adownlink control channel.

Additional features of the invention will be set forth in part in thedescription which follows and in part will become apparent to thosehaving ordinary skill in the art upon examination of the following ormay be learned from practice of the invention. The objectives and otheradvantages of the invention may be realized and attained by thestructure particularly pointed out in the written description and claimshereof as well as the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exemplary network structure of an Evolved UniversalTerrestrial Radio Access Network (E-UTRAN) as a mobile communicationsystem to which a related art and the present invention are applied;

FIG. 2 shows a radio interface protocol architecture between a terminaland a Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) based on3GPP radio access network standards;

FIG. 3 shows an exemplary view of a related art physical channelstructure for control channel transmission;

FIG. 4 shows an exemplary block diagram of a network structure for acell broadcast service;

FIG. 5 shows a warning message transmission process according to a firstembodiment of the present invention; and

FIG. 6 shows a warning message transmission process according to asecond embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

One aspect of the present invention is the recognition by the presentinventors regarding the problems and drawbacks of the related artdescribed above and explained in more detail hereafter. Based upon suchrecognition, the features of the present invention have been developed.

The present invention may be embodied in a 3GPP communicationtechnology, in particular, in the Universal Mobile TelecommunicationsSystem (UMTS) system, a communication apparatus and method thereof.However, the present invention may also be applied to all wired/wirelesscommunications to which the technical scope of the present invention canbe applied.

Hereinafter, description of structures and operations of the preferredembodiments according to the present invention will be given withreference to the accompanying drawings.

FIG. 5 shows a warning message transmission process according to a firstembodiment of the present invention. In the present invention, a warningmessage (which will be referred as ETWS (Earthquake and Tsunami WarningSystem) message hereafter) may be transmitted through a logical channelbroadcasting a control message to a plurality of terminals and atransport channel (i.e., Downlink Shared Channel; DL-SCH) mapping withthe logical channel.

As illustrated in FIG. 5, in a first step, a terminal (UE) may receivesystem information through a logical channel such as a Broadcast ControlChannel (BCCH). If the received system information contains schedulinginformation (or setup information or any other information related tothe warning (ETWS) message) of the warning (ETWS) message, the terminalmay further process a next step to receive the warning (ETWS) message.However, if the received system information does not contain thescheduling information of the warning (ETWS) message, the terminal maynot further process a next step. Here, the scheduling information mayinclude information about a time period that the warning (ETWS) messageis transmitted. Namely, the scheduling information may include specifictime information about when the warning (ETWS) message is transmitted.

In a second step, the terminal may receive or monitor a physicaldownlink control channel (PDCCH) for a certain time window/time periodallocated for a transmission of the warning (ETWS) message according tothe received scheduling information. Here, the terminal may receive aparticular radio network temporary identifier (RNTI) through thephysical downlink control channel (PDCCH).

In a third step, the terminal may receive the warning (ETWS) messagethrough a downlink shared channel (DL-SCH), which corresponds to thephysical downlink control channel (PDCCH), if the particular radionetwork temporary identifier (i.e., ETWS RNTI) is indicated in thephysical downlink control channel during the second step. However, ifthe particular radio network temporary identifier is not indicated inthe physical downlink control channel during the second step, theterminal may not receive the warning (ETWS) message through the downlinkshared channel.

Here, a warning (ETWS) message is transmitted or received through atransport channel such as a downlink shared channel (DL-SCH), which ismapped with a logical control channel (i.e., shared logical channel)that is used for a plurality of terminals to receives controlinformation commonly. Accordingly, the warning (ETWS) message may betransmitted through the logical control channel and the downlink sharedchannel by a base station. Also, the terminal may receive the warning(ETWS) message the logical control channel and the downlink sharedchannel.

Here, a base station (eNB) may retransmit the warning (ETWS) messageusing a HARQ (Hybrid Automatic Repeat reQuest) operation of the downlinkshared channel. Therefore, if the terminal does not completely receivethe warning (ETWS) message, the terminal may retry to receive thewarning (ETWS) message using the HARQ operation. The system informationand/or the warning (ETWS) message may be divided into a primary ETWSnotification and a secondary ETWS notification. Namely, the primary ETWSnotification and the secondary ETWS notification can be transmitted tothe terminal at same time. Or, under a certain circumstance, theterminal may receive the secondary ETWS notification after receiving ofthe primary ETWS notification.

FIG. 6 shows a warning message transmission process according to asecond embodiment of the present invention.

As illustrated in FIG. 6, in a first step, a terminal may receive ormonitor a physical downlink control channel (PDCCH) for a certain timewindow/time period allocated for a transmission of the warning (ETWS)message according to the received scheduling information. Here, theterminal may receive a particular radio network temporary identifier(RNTI) through the physical downlink control channel (PDCCH). Morespecifically, the terminal may periodically monitor the certain timewindow according to an ETWS period for a receiving of the warning (ETWS)message. The ETWS period may be a paging DRX (Discontinuous Reception)period, which set for the terminal to periodically receive a paging froma base station, or a multiple of the paging DRX period. Accordingly, ifthe ETWS period is same as the paging DRX period, the terminal maymonitor the warning (ETWS) message based on the paging DRX period.

In a second step, the terminal may receive the warning (ETWS) messagethrough a downlink shared channel (DL-SCH), which corresponds to thephysical downlink control channel (PDCCH), if the particular radionetwork temporary identifier is indicated in the physical downlinkcontrol channel during the first step. However, if the particular radionetwork temporary identifier is not indicated in the physical downlinkcontrol channel during the first step, the terminal may not receive thewarning (ETWS) message through the downlink shared channel.

Here, a base station (eNB) may retransmit the warning (ETWS) messageusing a HARQ (Hybrid Automatic Repeat reQuest) operation of the downlinkshared channel. Therefore, if the terminal does not completely receivethe warning (ETWS) message, the terminal may retry to receive thewarning (ETWS) message using the HARQ operation. The system informationand/or the warning (ETWS) message may be divided into a primary ETWSnotification and a secondary ETWS notification. Namely, the primary ETWSnotification and the secondary ETWS notification can be transmitted tothe terminal at same time. Or, under a certain circumstance, theterminal may receive the secondary ETWS notification after receiving ofthe primary ETWS notification.

The present invention may provide a method of receiving a warningmessage in mobile communication system, the method comprising: receivingcontrol information related to the warning message through a firstdownlink control channel; and receiving the warning message based on thereceived control information through a second downlink control channel,wherein the warning message is an Earthquake and Tsunami Warning System(ETWS) message, the first downlink control channel is a PhysicalDownlink Control Channel (PDCCH), the control information includes aRadio network Temporary Identifier (RNTI), the control informationincludes radio resource information for the warning message is to betransmitted, the second downlink control channel is a logical channelthat maps to a downlink shared channel (D-SCH), the control informationincludes a primary ETWS notification and a secondary ETWS notification,the primary ETWS notification is firstly received before the receptionof the secondary ETWS notification, and the second downlink controlchannel is a downlink shared control channel received by a plurality ofterminals.

It can be also said that the present invention may provide a method ofreceiving a warning message in mobile communication system, the methodcomprising: monitoring a physical downlink control channel (PDCCH)periodically for a certain time period; receiving a specific RadioNetwork Temporary Identifier (RNTI) related to the warning messagethrough the PDCCH; and receiving the warning message based on thespecific RNTI through a downlink control channel, wherein the warningmessage is an Earthquake and Tsunami Warning System (ETWS) message, thespecific RNTI is an ETWS RNTI, the downlink control channel is a logicalchannel that maps with a downlink shared channel (D-SCH), and thecertain time period is a time period for broadcasting the warningmessage.

Namely, the present invention has an effect of efficiently receiving awarning message with a minimum delay while efficient usage of radioresource(s) is achieved.

The present disclosure may provide potential solutions for ETWS(Earthquake and Tsunami Warning System) in E-UTRAN. Usually, usages ofETWS messages are very rare. Thus, UE may not need to monitor ETWSmessage every time for battery saving. However, once they take place, itwill be beneficial to help users receive frequent update of Earthquakeand Tsunami. For this reason above, the present disclosure may provideto have two steps to minimize UE battery power consumption. As for thefirst step, the eNB may transmit a primary indication of Earthquake andTsunami Warning to the UE. Then, for the second step, the eNB maytransmit a transfer/update of Earthquake and Tsunami Warning to the UE.Specifically, the eNB may provide the primary indication when the firstwarning is received. Afterwards, the eNB may prepare the second step totransmit updates of the warning. The UEs may periodically check if thereis primary indication of the warning or not while performing a normaloperation. If there is primary indication of the warning, the UEs moveonto the second step and so receive next updates. Here, during the firststep, the present disclosure proposes that the UE should check thewarning only with minimal effort while performing a normal operation. Onthe other hand, during the second step, the UE must receive incomingwarning messages with more effort.

More detailed description of the first step will be given as following.Start of the warning should be notified as quickly as possible. When UEis idle, paging message with a warning cause could be one of solutions.However, in most of cases, the paging message cannot reach to the UEs inconnected mode because the UEs in connected mode do not monitor thepaging message. Thus, following solutions can be used for connected UEs.

A first option is that indicating the start of the warning by changingof system information. The update of the warning is transmitted on acommon logical channel dedicated to broadcast of the warning. If thewarning begins, the system information carrying ETWS specific commonchannel configuration will be included in system information block(SIB). As a result, the UEs will receive change of system informationfor it. In this scheme, if the UEs find out that system informationcarrying ETWS specific common channel configuration is included in theSIB, the UEs may be notified the start of the warning. Then, the UEs maymove onto the second step.

A second option is that indicating the start of the warning by using anETWS specific RNTI on PDCCH. In most case, the connected UEs wouldfrequently monitor the PDCCH with some RNTIs. Thus, the presentdisclosure may propose to use the ETWS specific RNTI. Therefore, if UEsfinds the ETWS specific RNTI on the PDCCH, the UEs may be notified thestart of the warning. Then, the UEs may move onto the second step. Here,when the warning starts, the eNB may repeat the ETWS specific RNTI onavailable PDCCH channels for certain duration in order to make sure thatall UEs receive the ETWS specific RNTI. On the other hand, whenever theUE reads the PDCCH, the UE may need to check indication of the ETWSspecific RNTI on the PDCCH in addition to other RNTI. In this option,the UEs should check additional RNTI. To alleviate it, the eNB mayprovide some periodic opportunities in which ETWS specific RNTI isallowed to be transmitted.

More detailed description of the second step will be given as following.Once the warning is notified to the UE, frequent update of Earthquakeand Tsunami will be helpful for every user. In case that paging messageis used for the first step, after the warning begins, several pagingmessages would cause overload. Moreover, the warning may be provided bya multimedia messaging in E-UTRAN. Thus, the present disclosure proposesto implement transfer/update of the warning not on PCCH but on a commonlogical channel. (e.g. ETWS specific MTCH, CTCH or CCCH) Here, thecommon logical channel is mapped to DL-SCH.

The ETWS message on the DL-SCH may be periodically scheduled every ETWSperiod. Here, the ETWS period is not UE specific but cell specific.After receiving primary indication of the warning, the UEs may receiveDL-SCH to receive ETWS message every ETWS period. The ETWS message mayinclude details of the warning and/or update of the warning.

In addition, the PDCCH may help UE to save its battery. If the ETWSmessage is transmitted on DL-SCH, the PDCCH may indicate an ETWS RNTI.The eNB may perform HARQ re-transmission for the ETWS message on theDL-SCH. The UE periodically monitors the PDCCH within a time window tocheck if there is the ETWS RNTI. If the UE finds the ETWS RNTI, the UEreceives the ETWS message on the DL-SCH. If the UE fails to find theETWS RNTI within the time window, the UE may perform DRX and may waituntil the next time window.

Apart from the HARQ re-transmission on the DL-SCH, the eNB may repeattransmission of ETWS message. Further, the eNB may sometimes transmit anew ETWS message. Thus, such update information may be provided byeither the ETWS message or the PDCCH.

ETWS scheduling information should be provided to UE. The ETWSscheduling information can be provided by system information on a BCCH.If a paging message is used to carry the primary indication of thewarning, the paging message could also provide the ETWS schedulinginformation only to idle UEs. Moreover, ETWS channel configuration alsocan be carried on system information on BCCH.

In summary, the present disclosure provides two steps (i.e., step 1:Primary indication of Earthquake and Tsunami Warning, step 2:Transfer/update of Earthquake and Tsunami Warning) fortransmitting/receiving ETWS message, and proposes that the UEs receiveprimary indication of the warning by finding out inclusion of ETWSspecific common channel configuration in SIB or by receiving ETWSspecific RNTI on PDCCH, a common logical channel mapped onto DL-SCH isused to carry ETWS message, once the warning begins, the eNB providesperiodic opportunities on DL-SCH to carry ETWS message and UEs monitorsthe periodic opportunities every ETWS period, the PDCCH associated withthe DL-SCH indicates the ETWS RNTI. The System information on BCCHand/or paging message for primary indication transfers ETWS schedulinginformation, and the System information on BCCH carries ETWS channelconfiguration.

In some case, if system information carries the primary notification aswell as the secondary notification, it may not meet the delayrequirement on the primary notification. It is because a typical lengthof the BCCH modification period is more than the delay requirement (i.e.4 seconds). However, the present disclosure propose to implement thisscheme because E-UTRAN will have only one delivery mechanism for theETWS notification regardless of the type of the notification (i.e. theprimary or the secondary notification), if the primary notification iscarried on BCCH. Also, if it is the case, the same level of security(i.e. the digital signature based security) can be applied to theprimary notification as well as the secondary notification.

One possibility to meet the delay requirement of the primarynotification on BCCH is to have an ETWS specific BCCH modificationperiod carrying ETWS messages, such as an ETWS modification period. Thelength of the ETWS modification period may be equal to or more than thelength of the paging DRX cycle and should be less than the length of thenormal BCCH modification period. Here, the ETWS modification period hasno impact on operation of normal system information blocks becausedelivery of the ETWS message on BCCH does not change any other systeminformation. Only the ETWS messages on BCCH may follow the ETWSmodification period. It should be noted that configuration of ETWSdelivery including the length of the ETWS modification period will bebroadcast on the other SIB than the SIB carrying ETWS messages. The SIBcarrying the configuration of ETWS delivery follows the normal BCCHmodification period.

It should be noted that system information mentioned in presentdisclosure may be divided into the Master Information Block (MIB) and anumber of System Information Blocks (SIBs). The MIB includes a limitednumber of most essential and most frequently transmitted parameters thatare needed to acquire other information from the cell, and istransmitted on BCH. SIBs other than System Information Block Type1 maybe carried in System Information (SI) messages and mapping of SIBs to SImessages is flexibly configurable by scheduling Information included inSystem Information Block Type1. The SI messages are transmitted withinperiodically occurring time domain windows (referred to as SI-windows)using dynamic scheduling. The UE acquires the detailed time-domainscheduling (and other information, e.g. frequency-domain scheduling,used transport format) from decoding SI-RNTI on PDCCH. A single SI-RNTIis used to address System Information Block Type1 as well as all SImessages. The System Information Block Type1 configures the SI-windowlength and the transmission periodicity for the SI messages. The SystemInformation Block Type10 may contain an ETWS primary notification andthe System Information Block Type11 may contain an ETWS secondarynotification. More specifically, fields included in the SIB type 10and/or SIB type 11 may contains a parameter or value to indicate asource and type of ETWS notification, variations of the ETWSnotification, a warning type of the ETWS notification, securityinformation for the ETWS notification, and segment number of the ETWSwarning message segment, etc.

The purpose of the present disclosure is to transmit paging information(or message) to a UE in RRC_IDLE mode and/or to inform UEs in RRC_IDLEmode and UEs in RRC_CONNECTED mode about a system information changeand/or about an ETWS primary notification and/or ETWS secondarynotification. The paging information is provided to upper layers, whichin response may initiate RRC connection establishment, (e.g. to receivean incoming call). E-UTRAN may initiate the paging procedure bytransmitting the Paging message at the UE's paging occasion. The E-UTRANmay also indicate a change of system information and/or provide an ETWSnotification in the Paging message. Namely, if present, the indicationof an ETWS primary notification and/or ETWS secondary notification mayincluded in some field in the paging message.

Although the present invention is described in the context of mobilecommunications, the present invention may also be used in any wirelesscommunication systems using mobile devices, such as PDAs and laptopcomputers equipped with wireless communication capabilities (i.e.interface). Moreover, the use of certain terms to describe the presentinvention is not intended to limit the scope of the present invention toa certain type of wireless communication system. The present inventionis also applicable to other wireless communication systems usingdifferent air interfaces and/or physical layers, for example, TDMA,CDMA, FDMA, WCDMA, OFDM, EV-DO, Wi-Max, Wi-Bro, etc.

The exemplary embodiments may be implemented as a method, apparatus orarticle of manufacture using standard programming and/or engineeringtechniques to produce software, firmware, hardware, or any combinationthereof. The term “article of manufacture” as used herein refers to codeor logic implemented in hardware logic (e.g., an integrated circuitchip, Field Programmable Gate Array (FPGA), Application SpecificIntegrated Circuit (ASIC), etc.) or a computer readable medium (e.g.,magnetic storage medium (e.g., hard disk drives, floppy disks, tape,etc.), optical storage (CD-ROMs, optical disks, etc.), volatile andnon-volatile memory devices (e.g., EEPROMs, ROMs, PROMs, RAMs, DRAMs,SRAMs, firmware, programmable logic, etc.).

Code in the computer readable medium may be accessed and executed by aprocessor. The code in which exemplary embodiments are implemented mayfurther be accessible through a transmission media or from a file serverover a network. In such cases, the article of manufacture in which thecode is implemented may comprise a transmission media, such as a networktransmission line, wireless transmission media, signals propagatingthrough space, radio waves, infrared signals, etc. Of course, thoseskilled in the art will recognize that many modifications may be made tothis configuration without departing from the scope of the presentinvention, and that the article of manufacture may comprise anyinformation bearing medium known in the art.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

As the present invention may be embodied in several forms withoutdeparting from the spirit or essential characteristics thereof, itshould also be understood that the above-described embodiments are notlimited by any of the details of the foregoing description, unlessotherwise specified, but rather should be construed broadly within itsspirit and scope as defined in the appended claims, and therefore allchanges and modifications that fall within the metes and bounds of theclaims, or equivalents of such metes and bounds are therefore intendedto be embraced by the appended claims.

1. A method of receiving a warning message in mobile communicationsystem, the method comprising: monitoring a physical downlink controlchannel (PDCCH); receiving a specific Radio Network Temporary Identifier(RNTI) through the PDCCH; decoding the received specific RNTI on thePDCCH, wherein the specific RNTI is a System Information-RNTI (SI-RNTI),and wherein a time-domain scheduling is acquired from the decodedSI-RNTI; receiving system information through a downlink shared channel(DL-SCH) using the RNTI; and receiving the warning message based on thereceived system information, wherein the warning message is anEarthquake and Tsunami Warning System (ETWS) message, wherein the ETWSmessage is divided into a primary ETWS notification and a secondary ETWSnotification, and wherein the primary ETWS notification is contained ina system information block (SIB) type 10 and the secondary ETWSnotification is contained in a system information block (SIB) type 11.2. The method of claim 1, wherein PDCCH is periodically monitored for atime period for broadcasting the warning message.
 3. The method of claim1, wherein the received system information contains the primary ETWSnotification and the secondary ETWS notification.
 4. The method of claim3, wherein the primary ETWS notification is firstly received before areception of the secondary ETWS notification.
 5. The method of claim 1,wherein the system information is transmitted by a network withinperiodically occurring time domain windows.
 6. The method of claim 5,wherein the time domain windows is system information windows(SI-windows).
 7. The method of claim 6, wherein the DL-SCH is receivedfrom a start of the SI-windows to an end of the SI-windows.
 8. Themethod of claim 6, wherein the DL-SCH is received until the systeminformation is received.